The present invention relates to apparatus for conditioning discrete commodities, especially for heating metallic stock in a furnace. More particularly, the invention relates to improvements in apparatus wherein a conveyor system transports goods to be conditioned into, through and from at least one conditioning chamber or zone, e.g., into, through and from the interior of an annealing furnace for metallic springs or the like.
It is already known to heat metallic commodities in a furnace which is associated with a conveyor system including an endless belt or band which supports the commodities to be heated in random distribution. If the commodities are coil springs, their end convolutions are likely to become interlaced so that the freshly conditioned springs must be separated from each other in a time-consuming operation. The interlacing of randomly distributed coil springs presents additional problems if the springs are to be fed into an end grinder prior to further processing.
Attempts to insure an orderly transport of coil springs through the interior of a furnace include the provision of a conveyor system which employs two parallel wires spaced apart from each other by a distance less than the diameter of a coil spring. Thus, the springs can be placed onto the two wires in such a way that they form a single file of coaxial components during transport through the interior of the furnace. The wires are caused to pass through the furnace along a straight path. Those springs which issue from the furnace are ready to be introduced into or advanced past an end grinder. The loading of springs onto the two wires of the conveyor system can take place immediately at the discharge end of a coiling machine, i.e., successively formed springs are placed directly onto the conveyor system in the same orientation in which they issue from the maker. A drawback of the just described apparatus is that the wires advance through the furnace along a straight path. Therefore, if the springs are subjected to a longer-lasting heat treatment, the apparatus must include a relatively long and hence bulky and expensive furnace, and/or the conveyor system must be operated at an extremely low speed. If the furnace is short, the apparatus cannot be used for conditioning of different types of commodities unless the speed of the conveyor system is reduced to an economically unacceptable value. Furthermore, the furnaces which are associated with the two-wire conveyor system must have spaced-apart inlets and outlets for admission and evacuation of commodities, and this also contributes to the bulk and cost of the apparatus.